Conflicting guidance on IPv6

I recently noticed that Cable Guy is saying “don’t disable IPv6“. While I broadly agree with the approach and the reasons he suggests not to, I’ve not yet seen any down-side to disabling it, and I know we aren’t using the IPv6 technologies that Cable Guy mentions. But why did I turn it off? SharePoint’s Hyper-V performance and capacity guidance suggests that performance is improved by disabling it.

“Use IPv4 as the network protocol for Hyper-V guests. During the tests, better performance was observed when IPv4 was used exclusively. IPv6 was disabled on each network card for both the Hyper-V host and its guest VMs.”

In this case, I’m going with the SharePoint guys, especially when there’s a quantified test versus a theory, especially when it simplifies troubleshooting and not everyone is IPv6-fluent yet.